bus: simple-pm-bus: Probe the Layerscape SCFG node

Make the simple-pm-bus driver probe the Layerscape SCFG dt nodes and
populate platform_device structures from its child dt nodes.

This is now needed because its child interrupt-controller - ls-extirq -
is being handled as a platform_device instead of being initialized
through the IRQCHIP_DECLARE infrastructure which impeded its parent IRQ
retrieval through the blamed commit.

Note that this does not set ONLY_BUS because that enables the
of_platform_populate() call. The extra power management operations which
are enabled by that are not required but harmless.

Fixes: 1b1f04d8271e ("of/irq: Ignore interrupt parent for nodes without interrupts")
Signed-off-by: Ioana Ciornei <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
Link: https://patch.msgid.link/[e-mail]

drivers/bus/simple-pm-bus.c

···
 	{ .compatible = "simple-mfd",	.data = ONLY_BUS },
 	{ .compatible = "isa",		.data = ONLY_BUS },
 	{ .compatible = "arm,amba-bus",	.data = ONLY_BUS },
+	{ .compatible = "fsl,ls1021a-scfg", },
+	{ .compatible = "fsl,ls1043a-scfg", },
+	{ .compatible = "fsl,ls1046a-scfg", },
+	{ .compatible = "fsl,ls1088a-isc", },
+	{ .compatible = "fsl,ls2080a-isc", },
+	{ .compatible = "fsl,lx2160a-isc", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);